Self Portrait Suspended V (2004) by Sam Taylor-Wood, who is listed on Artfacts.net

Colin Gleadell on a website that predicts the success of artists' careers

This week sees the opening of New York's biggest contemporary art fair, the Armory Show. And, if that's not big enough, there are five other fairs in the city all showing contemporary art. The focus throughout is on the new artists who are feeding the frenzy among collectors to get on the bandwagon early in an artist's career. In the current mood of optimistic speculation, one can only guess that the uptake will be strong.

But, with so much art available, how are buyers making their choices? According to saleroom experts, buyers are much better informed than they used to be. So what sort of information are they getting and where from?

One source is the exclusive, word-of-mouth network of dealers, artists, critics and museum curators who reach a kind of consensus on what is good and might be worth buying. Another is the internet, which is available to all.

In addition to artist and gallery websites, auction-price information is readily available. The best sites are artnet.com, artmarketresearch.com, art-sales-index.com, and artprice.com. Their perspectives are, obviously, on the past. But now a relative newcomer has brought gallery and auction sales information together in an attempt to predict the future.

Artfacts.net, which will be at the Armory Show, began as an exhibition guide with thousands of artists arranged in alphabetical order. "Then," says director Marek Claassen, "we asked ourselves if it would be possible to describe an artist mathematically, to predict an artist's career using econometrical methods."

Claassen developed a ranking system awarding points based on the international importance of the museums or galleries where the artist had shown. "From then on, there was no stopping us."

Today, nearly 60,000 internationally recognised artists are listed. The number of points awarded reflects the importance of the artist in the eyes of the curators who select the artists for exhibitions. From these charts it is possible to get an idea of an artist's standing on the international exhibition circuit. The key points from the prediction point of view are the sudden rises in the flow charts which suggest the revaluation of an artist's career or the blossoming of a new one.

Although Artfacts was not conceived as a tool to analyse the market, Claassen soon recognised that it could be, and last year added an economic flow chart of artists' sales at auction. "We wanted to show that there are connections between the two charts," says Claassen. "If the artist's exhibition ranking goes up significantly, it is likely the auction chart will follow the pattern. That is the reason we put it in."

Sometimes, as with Damien Hirst, the graphs rise together. Other times, as with Sam Taylor-Wood, they go up and down at separate points. "This is the perfect curve," says Claassen, "as it shows a delayed interaction between exhibitions and auction sales."

Then there are the artists who have no auction records. When their exhibition ranking keeps going up the odds are that sooner or later they will impact on the re-sale market.

Artists currently showing in the UK provide a cross-section of how these chart movements can be applied. At the Benjamin Brown gallery in Cork Street are the embroidered pictures of Italian conceptual artist Alighiero Boetti. Auction sales of Boetti's work rose sharply in the late 1990s in response to major exhibitions in Turin, Frankfurt and London. In 2002, Boetti became one of Artfacts's top 100 ranked artists with an exhibition in Houston, and last year the market responded with another sharp rise in auction activity.

A younger generation artist is the German painter, sculptor and performance artist Jonathan Meese, whose work is on show at Modern Art in Bethnal Green. Meese's exhibition ranking has improved from 725 in 2000 to 227. Auction sales have begun only recently, but strong sales at Modern Art indicate that the market will follow his improved ranking.

At the most speculative level are artists such as Mark Titchner, currently showing at the Arnolfini in Bristol. Although he has not sold at auction, Titchner's ranking has risen from 12,000 in 2002 to 3,900, and his gallery prices have doubled in two years.

And what if the market collapses? "There will be winners and losers in a bear market also," says Claassen.